During certain types of surgery, particularly in connection with chest cavity surgery, the patient frequently loses large amounts of blood. Ordinarily, the lost blood is aspired away and the patient is given a transfusion of donated blood to make up for the lost blood. An alternative arrangement is to provide an autotransfusion device which will collect the blood lost by the patient and transfuse this blood into the patient's circulatory system.
There are disclosed in the prior art various systems for autotransfusion. For example, in the U.S. Pat. No. 3,191,600 (Everett) an autotransfusion apparatus is disclosed which includes a vacuum source and a plurality of suction tips for immersion in pools of blood. The blood is collected in a collection chamber and is returned to the patient through a oneway valve. Another autotransfusion device is disclosed in U.S. Pat. No. 3,492,991 (Dyer) and includes a container equipped with a filter through which the blood is gravity fed back to the patient. In U.S. Pat. No. 3,993,067 (Schachet et al) an autotransfusion device is disclosed in which the blood is forced back into the patient by pressure in the collection chamber. Still another autotransfusion device is disclosed in U.S. Pat. No. 4,047,526 (Reynolds et al). This patent discloses a collection chamber in which blood is continuously aspirated. A blood bag with an outwardly urged spring is connected to the collection chamber to withdraw some of the blood therefrom. The blood collected in the blood bag is then later reintroduced into the patient. There has also been disclosed in the prior art a spring operated device which forces blood from a blood bag into the patient. Such a device is disclosed in U.S. Pat. No. 3,565,292 (Jinotti).
The applicants of the present invention have previously filed an application for a novel autotransfusion device which is efficient and simple to operate. This application is Ser. No. 290,666 and was filed on Aug. 5, 1981 now U.S. Pat. No. 4,424,053. Applicants have also filed a continuation-in-part application on Aug. 14, 1981, now U.S. Pat. No. 4,445,884 with an air purge unit for applicant's autotransfusion device. This air purge unit insures that all air within the collection chamber is automatically eliminated before the blood is reintroduced into the patient's circulatory system.